IMPACT OF COVERING IRRIGATION CANALS ON EVAPORATION RATES IN ARID AREAS

Abstract

Water is the essence of life; thus preserving enough quantities and good quality of water will elevate the standards of living and health of communities. Egyptian government approved Toshka New Valley project to help deal with the rapidly growing population of the country. The project entails building a series of canals; the main is Sheikh Zayed canal - to irrigate portions of the Western Desert of Egypt. It is expected that the recovered land will become home to three million residents by 2020 and cultivate about 550000 feddans. Toshka is a very arid area with high air temperatures; thus very high evaporation rate; about 3 billion m3/year. Researches showed that in the near future Egypt will face scarcity of water. So saving water from Sheikh Zayed canal by reducing evaporation will provide additional source of water to the area. This research aim is to estimate evaporation rate from the canal and its main branches. Variable configurations and spacing of covering canals were chosen to reduce evaporation and at same time allow for re-aeration and other water quality parameters to meet their standards. It was found that full coverage calculated evaporation amount is about 9 million m3/year which could drip irrigate 35000 feddans of wheat per year which is about 7% of the total area of the land intended to be cultivated in Toshka project.